Gravity-closing scoop



Feb. 14, 1967 GROSPAS GRAVITY-CLOSING SCOOP 3 Sheets-Sheet 1 Filed July 29, 1963 3 Sheets-Sheet 2 Feb. 14, 1967 P. 'GROSPAS GRAVITY-CLOSING SCOOP Filed July 29, 1963 l ff Feb. 14, 1967 P. GROSPAS GRAVITY-CLOSING SCOOP 3 Sheets-Sheet 5 Filed July 29, 1963 United States Patent 3,303,590 GRAVITY-CLOSING SCOOP Pierre Grospas, Le Continental, Place des Moulins, Monte Carlo, Monaco Filed July 29, 1963, Ser. N 0. 298,315 7 Claims. (Cl. 37-183) The present invention relates to scoops of the type comprising at least two gripping members, such as shells, assembled to a pusher member by a first set of articulated joints and movable in relation to one another, and a device for closing these members comprising a closing control member such as a cable or a chain which is connected, on the one hand, to the pusher member and, on the other hand, to a second set of articulated joints for the gripping members by means of a pulling member so that, when it is actuated, a force is exerted which acts vertically and downwardly on the pusher member and a force is exerted which acts vertically and upwardly on the pulling member.

In this manner, the forces simultaneously cause the scoop to penetrate into the material to be handled, by the relative movement of the pusher and pulling members, and the gripping members to close.

It is known that the output of a scoop of this type essentially depends on the filling rate of the gripping members each time they close, and that this filling rate itself directly depends on the resultant force causing penetration of the scoop into the materials to be handled, this resultant force being the sum of the weight of the scoop and the aforementioned force acting on the pusher member of the scoop.

The present invention has specifically for an object to greatly increase the output of a scoop of the aforementioned type and to this end, such a scoop is characterised in that the control member connected by means of the pulling member to the second set of articulated joints for the gripping members is connected to a member having a large mass by mechanical connecting means which are integral with the pusher member, means which are independent of the gripping members and which act directly on said member having a large mass being provided to raise said member to a high position in relation to the pusher member and to keep it in this position, and means being provided to subsequently liberate said member having a large mass which then, by means of simple gravity,

causes the gripping members to close while increasing the downward thrust exerted on the pusher member of the scoop.

According to an advantageous constructional feature of such a scoop, said member having a large mass is shaped so as to constitute a trepan which may be disconnected from the control member acting on the gripping members and is assembled in such a way that it may be displaced in the low position between the gripping members when these are open.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which show some embodiments thereof by way of examples, and in which:

FIGURES 1 and 2 are diagrams showing two different embodiments of known scoops of the type to which the invention relates,

FIGURES 3, 4 and 5 are diagrams showing three different embodiments of scoops in accordance with the invention,

FIGURE 6 shows a vertical section of a particular embodiment of the scoop of the type shown diagrammatically in FIGURE 3, the scoop being provided with a member having a large mass constituting the trepan and its gripping members being shown in the open position,

FIGURE 7 is a lateral view of the same scoop with its gripping members in the closed position, and the trepan being not shown so as to simplify the drawing, and

3,303,590 Patented Feb. 14, 1967 FIGURE 8 is a detail view of the scoop shown in FIG- URES 6 and 7, illustrating the device enabling the trepan to be connected or disconnected to or from the control member for closing the gripping tongs.

Reference will firstly be made to FIGURE 1 which diagrammatically shows a scoop of the known type. This scoop comprises a pusher member 1 suspended from hoisting cables 3 and on the lower part of which are articulated, at 5, two gripping members or shells 7. The shells are, moreover, articulated at 6 to a pulling member 9 which is secured to a pulley 11. A control cable 13 for closing the shell 7 is connected at 15 by one of its ends to the upper part of the pusher member 1, passes around the pulley 11 and its other end connects it to a control winch shown diagrammatically at 17 and assembled on a fixed frame.

R designates the value of the resistance force F opposing the closing of shells 7 by the weight of the assembly which is substantially formed by the pulling memher 9 and the shells 7 and by the material to be handled located between the shells 7, and it may consequently be deduced that in order to obtain closure of these shells it will be necessary to exert a traction force F having a value at least equal to the absolute value R of force F upwardly on the axis of the pulley 11. The traction force F breaks down into forces F and F having a value R/2 and vertically applied to the two parallel structures of the control cable 13 wound around the pulley 11. The force F creates a reaction force F having a value R/2 and of opposite direction, vertically and downwardly applied onto the pusher member 1 to the fixing point 15 of the cable 13 thereon. The force F having a value R/2, is that which must be developed by the winch for closing the shells.

By designating by A the value of the weight of this pusher member 1, it may be said that the value P of the thrust force, sum of this total weight and of the force F with which the scoop is then vertically and downwardly applied on the materials to be handled during closing, the hoist cables 13 being relaxed, verifies the following relation:

Supposing, for example, the value A is 1000 kilo gramsand that the value R is 1500 kilograms, one obtains:

P=1750 kilograms FIGURE 2 shows the diagram of a scoop of the same type as that shown in FIGURE 1 but provided with a simple damping devioe com-prising pulleys 11a and 11b. The same reference numerals designate the same elements.

In this case, and maintaining the same meanings for letters P, A and R, one may write the same term:

And, by adopting the same numerical example as above, one obtains:

P=2,000 kilograms It will be seen that, by providing a simple pulley bl0ck assembly, it is possible, as is well known, to use a control winch 17 having reduced power of a value of R/ 3 by comparison with the preceding solution and moreover providing the advantage that it thrusts the scoop more firmly downwards into the handled materials.

Although, in practice, it is not possible to envisage a pulley block assembly comprising a very high number of pulleys, it is nevertheless pointed out that, taking this number to infinite limits, a thrust force P would be obtained having by way of limit value which could possibly 3 be obtained: P ='A+R, this limit value being 2,500 kilograms for the numerical example chosen.

Reference will now be made to FIGURE 3 diagrammatically illustrating the most simple embodiment of the invention. The same reference numerals are used as in FIGURES 1 and 2 for corresponding elements having identical functions.

In accordance with the invention, the closing control cable 13 is, instead of being directly connected to a control winch after being passed around at least one return pulley, here connected to a member 21 having a large mass after being passed around a pulley 19 suspended from the upper part of the pusher member 1. A cable 23 attached to this heavy member 21 may be actuated by the control winch 25 which, it is specified, in no way has the same operational method as winch 17 in the case of FIGURES 1 and 2. In point of fact, this winch 21; is designed to act directly on the heavy member 21 when it is driven in order to raise said member to a high position in relation to the pusher member 1 and to hold it in this position, then subsequently to release the member 21 having a high mass when it is freed, and it thus causes the shells 7 to close because of the force of gravity.

. Assuming that the force F hereinbefore defined has a value R, it will be seen that, in order to ensure closure of the shells 7, it is necessary that the weight of the member 21 has a value at least equal to R. Consequently, the reaction force F due to the combined action of force F and the weight of the member 21 on the pusher member 1 by means of the axis of pulley 19, is vertically and downwardly directed and has a value 2R. And, still designating the value of the weight of the pusher member 1 by A, and the value of the force of the vertical downward thrust of the scoop onto the material to be handled by P, the relation, in the case of FIGURE 3,. is written as follows:

P=A+2R (3) Taking the same numerical example as before, P=4,000 kilograms is obtained. It is noted that, for a same force ensuring closure of the shells, a considerable increase in the thrust force P is obtained and consequently of the output of the scoop. This highly favourable result is caused by the fact that the force closing the shells, which is necessarily transmitted to the pusher member whereon the said shells are articulated, is no longer a traction force of a cable directed vertically upwards, as in the case of known scoops shown in FIGURES 1 and 2, but a gravity force of a member having a large mass and which is directed vertically downwards.

It may also be worthwhile, should it be wished to reduce the value of the mass of member 21, to provide a pulley block assembly as of ,the type diagrammatically illustrated in FIGURE 4. In this case, the member 21a has a Weight value at least equal to R/2.

With the same notes as before, it is then possible to write, in the case of this FIGURE 4, the relation:

Taking the same numerical example as hereinbefore, P=.3,250 kilograms is obtained, that is to say a thrust value which is even higher than the limit value of 2,500 kilograms which it is theoretically possible to obtain, in the case of the same numerical example, with scoops known heretofore.

FIGURE diagrammatically shows another embodiment of a scoop in accordance with the invention. In this embodiment, the pulling member is connected by rod 27 to an articulation 29 at the end of a beam 31, the pivot 33 of which is rigidly connected to the upper part of the pusher member 1. The other end 35 of the beam 31 is articulated to a rod 37 supporting the member having a large mass 21a, the weight of which still has a value of R/2 in this embodiment since the arm of th lQ QIj 3 34 4 is twice the length of the arm of the lever 29-31. Here again, the same relation is obtained:

as is the case in FIGURE 4.

Reference will now be made to FIGURES 6, 7 and 8 so as to describe in greater detail the construction of a scoop, analogous in'principle to that diagrammatically illustrated in FIGURE 3, this scoop being moreover notable in that the member having a large mass is shaped to constitute a trepan so that the scoop can then act as a tool for boring and excavating soil. The same reference numbers are used in FIGURES 6, 7 and 8 and FIGURES 1 to 5 for corresponding elements having identical functions.

FIGURE 6 shows a vertical section of the scoop and the trepan.

The scoop is shown with its shells 7 in the open position and the trepan 21 is shown in the working position, at the end of its travel, the moment in which it has penetrated into the ground.

This scoop comprises a pusher member 1 which slides in a pulling member 9.

These rigid members 1 and 9 sliding in relation to one another are moreover interconnected by articulations, which are respectively designated by 5a and 5b and 6, to the two shells 7. The connection between these articulations 5a and 5b is effected by means of oscillating links 39, the method of action of which will hereinafter be explained.

The opening and closing of the shells 7 is efiected by the relative rectilinear displacement of the pusher and pulling members 1 and 9 guided by a groove 41. This relative displacement is caused by the thrust action which is directed vertically downwards and exerted on the pusher member 1 under the action of the weight of the trepan 21 by means of the closure device comprising two cables '13, each anchored at a tie point 43 to the pulling member 9, on the one hand, subsequently passing over pulleys 19, the axis of which are integral with the pusher member 1 and anchored, on the other hand, to an anchoring system 45 wherefrom may be suspended the heavy trepan 21; this system 45 is illustrated in detail in FIGURE 8 and will hereinafter be described. The stress thus exerted on the pusher member 1 is transmitted to the shells 7 by the oscillating links 39.

The oscillating links 39 have two tie axis 5a and 5b. The tie axis 5a eifects, when the shells 7 are displaced, a curvilinear trajectory. The tie axis 5b then follows a vertical rectilinear trajectory. The links 39 are consequently caused to oscillate during closure of the shells 7 and assume positions such that the thrust force transmitted to the lower attacking edges of the shells 7 assists, when these begin to close, the penetration of the shells 7 into the material to be handled or into the ground and, subsequently, the tightening of the shells 7 against one another when the closure movement has been completed.

The relative displacement of the pusher and pulling members 1 and 9 is limited, upon the one hand, by the shells 7' coming up against one another and, on the other hand, by a stop 47 located on the pusher member 1 and entering into contact with the pulling member 9 when the opening movement has been completed. Adjustable fixing means for the stop 47 onto the thrust body 1, shown diagrammatically by tightening members 49, enables the position of the stop 47 on the pusher member 1 to be rapidly modified so as to allow for a larger relative amount of travel between the pusher and pulling members 1 and 9 and, consequently, increased opening of the shells. This possibility is used in particular so as to be able to increase the diameter of action of shells 7 and, if necessary, to work beneath the tubing, in a bore holewhich has been partially tubed with a greater diameter than that of the tubing.

The operational method of the scoop hereinbefore described is as follows:

(1) Use of the trepan as a member for perforating the ground The scoop is suspended by means of a collar or flange 51 provided with a suspension mounted on a bore stop 53 at a few centimetres from the bottom of the well, the shells 7 being opened. The trepan 21, suspended by its operational cable 23 and sliding in guide slides 55 which are part of the traction body 9, is caused to have an alternate raising and dropping movement by means of a suitable ramming device provided on the ground, not illustrated.

(2) Operation of the scoop itself The trepan 21 having dislodged the materials at the foot of the hole, the next step is to extract the detritus. This is effected by means of the following operations:

(a) The scoop is located at the bottom of the hole, with the shells open and engaged in a circular groove made by a peripheral part of the trepan;

(b) The trepan 21 is outwardly moved towards the hooking device 45 so as to engage hooks 57 of the trepan 21 in the hook 59 of the hooking device 45. As may be seen from FIGURE 8, this hooking device 45 comprises hooks 61, the bodies of which are suspended from cables 13 by means of axis 63 around which they may oscillate when the member 65 constituting the upper part of the trepan 21 comes into contact with hook 45 during the upward movement of the trepan 21.

A system of links 69 and 71, which are articulated among themselves by means of the axis 73, are also assembled on the hooking device 45 by means of an axis 67.

The upward movement of member 65, coming into contact with the surfaces 75 of the hook 61 constituting cams, forces the hooking devices 45 to withdraw. The links 69 and 71, due solely to their weight, then occupy the positions for which ends 77 of the links 71 extend beyond the hook 61. The member 65 thus encounters the ends 77 of the links 71 in such a Way that the latter effect a vertical ascending movement by pivoting around the axes 73 so as to occupy the position shown in broken lines in FIGURE 8. As soon as the hooking parts of hooks 57 and the member 65 have passed beyond the hooking parts of hooks 59, the hooking devices 45 tend, by mere gravity, to return into position, the links 71 still being raised above the member 65.

If at this moment the trepan 21, and consequently also member 65, is allowed to descend once more, the said member engages by means of its hooks 57 in hooks 59 and the suspension of trepan 21 to the closure system of the shells is elfected.

The gravity descent of trepan 21, which is effected when its operating cable 23 is released, causes the weight of the trepan 21 to fall onto the control cable 13 and, by means of pulleys 19, onto the pusher member 1. The closure of shells 7 is initiated by starting with an application of pressure to links 39, transmitted to shells 7 which are pivoted around axes 6 until they are completely closed.

The trepan 21 remains suspended from the closure device and exerts a constant force on the cable 13 thus ensuring locking of the shells 7 in the closed position shown in FIGURE 7.

It is then suflicient to raise the scoop by means of hoist cables 3 and to bring it into the open at the desired height. When this is reached, the scoop is immobilised and the trepan 21 is raised by exerting traction on its control cable 23. From this moment, the traction forces exerted by the trepan 21 in the vertical upward direction onto the ties 43 of the cable 13 on the pulling member 9 decrease so that a relative downward movement of the member 9 in relation to the pusher member 1 is initiated and continued as long as the trepan 21 moves upwards until the upward positioning of the hooking devices 45,

effected when the pulling member 9 completes its course against the stop 47, is obtained. Thus, during the relative movement of the pulling member 9 and the pusher member 1, progressive opening of the shells 7 is obtained.

From this moment, an additional upward movement of the trepan 21 frees the hooks 57 from hooks 59. By pursuing this upward course, the trepan 21 continues to thrust the links 71 upwards, these being thrust by member 65 as will be understood from FIGURE 8. When this member 65 is sufliciently high, it no longer retains the links 71 which fall back and the ends 77 of which rest on the edges of hooks 59, as shown in FIGURE 8.

If, at this moment, the trepan 21 is allowed to drop down again, the member 65 will enter into contact with the upper part of the links 71 along the edges of the hooks 57, these parts of the links having the shape of inclined planes 79 forming cams. By acting on the inclined planes 79, the members 65 outwardly thrust the links 71 which hook, by stop surfaces 81, onto the hooks 59. The hooking devices 45 oscillate outwards and withdraw until the end of the passage of the trepan which becomes disengaged and ready to reassume its position so as to once more commence the cycle of operations hereinbefore described.

As shown in FIGURE 7, screens 83 may advantageously be fixed to the pusher member 1 so as to increase the capacity of the scoop by preventing the detritus from falling outside the shells and according to the slope of the extracted detritus. It is advantageous to provide these measures so as to fully benefit from increased capacity for soil excavation by a boring tool such as that described.

I claim:

1. A scoop comprising at least two gripping members such as shells mounted by a first set of articulated joints on a pusher member and movable in relation to one another, and a closure device for said members comprising a closure control member connected, on the one hand, to the pusher member and, on the other hand, by means of a pulling member to a second set of articulated joints for said gripping members so as to exert, when actuated, a force which acts vertically and downwards on said pusher member and a force acting vertically and upwards on said pulling member, said control member also being connected to a member having a large mass, means independent of said gripping members and acting directly on said member having a large mass to raise said last named member to a high position in relation to said pusher memher and to keep it in said position, and for subsequently releasing said member having a large mass which then, by means of gravity, causes said gripping members to close while increasing the downward thrust exerted by said pusher member.

2. A scoop comprising at least two gripping members such as shells mounted by a first set of articulated joints on a pusher member and movable in relation to one another, and a closure device for said members comprising a closure control member connected, on the one hand, to the pusher member and, on the other hand, by means of a pulling member to a second set of articulated joints for said gripping members so as to exert, when actuated, a force which acts vertically and downwards on said pusher member and a force acting vertically and upwards on said pulling member, said control member also being connected to a member having a large mass by latching connection means secured to said control member, said latching connection means being normally disconnected from said member having a large mass, means independent of said gripping members and acting directly on said member having a large mass to raise said last named member to a high position in relation to said pusher member for connection with said latching connection means and to keep it in said position, and for subsequently releasing said member having a large mass which then, by means of gravity, causes said gripping members to close while increasing the downward thrust exerted by said pusher member.

3. A scoop as set forth in claim 2, and wherein the articulated joints of said shells which are furthest from the longitudinal axis of the scoop comprise oscillating links.

4. A scoop as set forth in claim 2, and wherein said member having a large mass is shaped to constitute a trepan which is disconnectable from said latching connection means acting on said gripping members and located so that in the low position it can move between said gripping members when the latter are in the open position.

5. A scoop as set forth in claim 4, wherein said latching connection means comprises a pivoting hook, said hook having at its base a surface forming a first cam to cause said hook to pivot when said trepan is moved upwards, said hook also comprising a member pivotally mounted thereon and having a surface forming a second cam adapted to assume a position suitable for causing pivoting off the hook when the trepan is moved down- .8 wards, said hook of said control member co-operating with a hook integral with the trepan.

6. A scoop as set forth in claim 2, wherein said pusher and said pulling members are constituted by parts which are slidable in relation to one another.

7. A scoop as set forth in claim 6, wherein said members which are slidable in relation to one another cooperate with adjustable stops acting to determine the maximum open position of said gripping members.

References Cited by the Examiner UNITED STATES PATENTS 1,544,969 7/1925 Cooper et a1. 37187 FOREIGN PATENTS 1,237,251 6/1960 France.

ABRAHAM G. STONE, Primary Examiner.

J. R. OAKS, Assistant Examiner. 

1. A SCOOP COMPRISING AT LEAST TWO GRIPPING MEMBERS SUCH AS SHELLS MOUNTED BY A FIRST SET OF ARTICULATED JOINTS ON A PUSHER MEMBER AND MOVABLE IN RELATION TO ONE ANOTHER, AND A CLOSURE DEVICE FOR SAID MEMBERS COMPRISING A CLOSURE CONTROL MEMBER CONNECTED, ON THE ONE HAND, TO THE PUSHER MEMBER AND, ON THE OTHER HAND, BY MEANS OF A PULLING MEMBER TO A SECOND SET OF ARTICULATED JOINTS FOR SAID GRIPPING MEMBERS SO AS TO EXERT, WHEN ACTUATED, A FORCE WHICH ACTS VERTICALLY AND DOWNWARDS ON SAID PUSHER MEMBER AND A FORCE ACTING VERTICALLY AND UPWARDS ON SAID PULLING MEMBER, SAID CONTROL MEMBER ALSO BEING CONNECTED TO A MEMBER HAVING A LARGE MASS, MEANS INDEPENDENT OF SAID GRIPPING MEMBERS AND ACTING DIRECTLY ON SAID MEMBER HAVING A LARGE MASS TO RAISE SAID LAST NAMED MEMBER TO A HIGH POSITION IN RELATION TO SAID PUSHER MEMBER AND TO KEEP IT IN SAID POSITION, AND FOR SUBSEQUENTLY RELEASING SAID MEMBER HAVING A LARGE MASS WHICH THEN, BY MEANS OF GRAVITY, CAUSES SAID GRIPPING MEMBERS TO CLOSE WHILE INCREASING THE DOWNWARD THRUST EXERTED BY SAID PUSHER MEMBER. 